Borrowings (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Debt Disclosure [Abstract]
Borrowings	$ 771,482	$ 906,635
Maximum outstanding FHLB advances at any month end	1,200,000	1,100,000
Average outstanding FHLB advances	$ 1,000,000	$ 895,000
Federal Home Loan Bank, Advances, Activity for Year, Average Interest Rate at Period End	1.20%	1.90%